Circuit controller



May 27, 193% F. E. (:ASE

CIRCUIT CONTROLLER Filed Aug. 24, 1927 wc {o o t m5 t m A 5 mm FPatented May 27, 1930 UNITED STATES PATENT OFFICE FRANK E. CASE, OFERIE, PENNSYLVANIA, ASSIGNOR TO GENERAL ELECTRIC CO]!!- PANY, ACORPORATION OF NEW YORK CIRCUIT CONTROLLER Application filed August 24,1927. Serial No. 215,228.

This invention relates to the control of electric circuits and moreparticularly to circuit controllers having one or more circuitcontrolling contacts arranged to be operated by means of rotatablecams,-and the princi-- pal object of the invention is to provide foroperation of the contacts independently of the rotation of the operatingcams.

While not necessarily limited thereto, the present invention isparticularly advantagoons in cam operated circuit controllers having aplurality of circuit controlling con tacts arranged to be operated in apredetermined sequence for controlling the circuit of an electric motoror other translating device. By means of the present invention,automatic simultaneous operation of the several circuit controllingcontacts of the controller to their circuit opening positions may beproduced upon the occurrence of overload or other abnormal conditions inthe circuit of the motor, or other translating device, irrespective ofthe angular position of the operating cams.

With the present invention embodied in a controller having a pluralityof circuit controlling contacts arranged to be operated in sequencethrough the agency of a rotatable cam shaft, the cam shaft is movablymountcd so that it may be shifted bodily out of normal operatingrelation with the switch contacts under the control of anelectroresponsive device, such as an electromagnet or the like. In thisway all of the switch members may be moved simultaneously to apredetermined circuit controlling position with the cam shaft in anyangular position. The controlling electromagnet preferably is energizedin accordance with the current in the motor circuit controlled by thecontroller so as to permit the cam shaft to move out ofoperatingrelation with the switch member and thereby effect operation of thecontroller contacts in the circuit opening position upon the occurrenceof overload conditions in the motor circuit.

In the accompanying drawing, the single figure diagrammaticallyillustrates a motor controller embodying a preferred form of the presentinvention arranged to provide automatic overload protection for themotor.

The motor controller illustrated in the.

22, 23, with which the respective members 10, 11, 12, 13, are provided.

The cams 14, 15, 16, 17, are angularly displaced on the cam shaft 18, asindicated in the drawing, so as to operate the switch mem bers 10, 11,12, 13, in a predetermined sequence. Thus, the switch member 10 is firstoperated to the circuit closing position upon rotation of the operatinghandle 19 in the direction indicated by the arrow in the drawand theswitch members 11, 12 and 13 are successively closed upon continuedrotation of the cam shaft 18.

In accordance with the present invention the cam shaft 18 is so mountedthat the operating cams 1-1, 15, 16, 17, may be moved out of operatingrelation with the switch members. As shown diagrammatically in thedrawing, the cam shaft '18 is rotatably mounted in suitable bearings atthe/ends of the arms 21 extending in spaced relation from the pivotbearing 25, which it will be understood is supported in suitablebearings. This mounting permits the cam shaft 18 to swing bodily aroundthe pivot bearing 25 and also rotate in the bearings in the ends of thearms 21. The cam shaft 18 normally is maintained in cooperating relationwith the rollers on the switch members by means of the toggle mechanism26. The toggle mechanism comprises the-lever 27 and the link 28. Thelever 27 is provided with an operating handle and is mounted upon thepivot 29 and connected through the link 28 with the cam shaft 18. p

\Vhcn the toggle mechanism 26 is extended as illustrated in the drawing,the engagement of the link 28 with the pin 30 serves to lock the togglemechanism over center so as to hold the cam shaft 18 in the positionshown. The toggle mechanism 26 may be collapsed either by operating thelever 27 or by means of the electroresponsive tripping mechanism 31. Asshown in the drawing, the tripping mechanism 31 comprises theelectromagnet 32 having its armature 33 connected to operate the bellcrank arm 34 about the pivot Upon energization of the electromagnet toattract the armature 33, the free end of the bell crank 31 engages withthe toggle mechanism 26 to collapse the same and therebypermit the camshaft 18 to swing downward about the pivot 25 out of the position inwhich it is shown in the drawing.

The controller, constructed as just described, is particularly adaptedto control the energizing circuit of an electric motor, although thecontroller may be used in other service. As shown diagrammatically inthe drawing the controller is connected to control the energization andoperation of the motor 36 which is arranged to be energized from thesupply line T with the speed regulating resistors R R R in the motorcircuit. The switch member 10 is connected to open and close theenergizing circuit for the motor 36, while the switches, 11, 12, 13 areconnected respectively to short circuit the regulating resistors R R RThe electromagnet 32 is connected directly in the eneri gizing circuitof the motor to be energized in accordance with the current therein.

The operation of the controller is as follows: Upon rotation of theoperating handle 19 in the direction indicated by the arrow in thedrawing the cam 14 cooperates with the roller 20 to move the switchmember 10 from its biased position in which it is shown to the circuitclosing position. This completes a circuit extending from the supplyline T through the operating winding of the electromagnet 32, the switchmember' 10, the speed regulating resistors R R R and the field andarmature windings of the motor 36, as indicated in the drawing. Uponcontinued movement of the operating handle 19, the switch 10 ismaintained in the closed position and the switches 11, 12, 13, areoperated successively by the cams 15, 16, 17 to short circuit theregulating resistors R R R step by step. This results in full speedoperation of the motor 36. Upon the return movement of the operatinghandle 19, the switches 13, 12, 11, are successively opened to reinsertthe resistors R R R in the motor circuit and the switch 10 is finallyoperated to the circuit opening position to interrupt the motor circuit.

The electromagnet 32 is so designed that during normal conditions ofcurrent flow in the motor circuit the armature 33 remains in theunattracted position. In case, however, motor 36 should becomeoverloaded with a resulting abnormal flow of current through theoperating winding of the electromagnet 32, the armature 33 is attracted.As previously described, this results in tripping the toggle mechanism26 to permit the release of the cam shaft 18. \Vith the toggle mechanism26 collapsed the axis of rotation of the shaft 18 is moved so as tosimultaneously effect operation of any of the switches 10, 11, 12, 13that may be in the circuit closing position to the circuit openingposition irrespective of the angular position in which the cam shaft 18may be. The cam shaft 18 is readily returned into the normal operativeposition by means of the resetting lever 27.

In this way overload protection for the motor 36 is provided withoutrequiring any contacts in the circuit other than those necessary for thenormal control of the motor.

It will be understood that the apparatus shown is illustrative and thatvarious changes and modifications therein may be' made without departingfrom the-spirit and scope of the invention.

\Vhat I claim as new and desire to secure by Letters Patent of theUnited States is 1. The combination of a plurality of movable switchmembers, a movable operating member therefor, means for movably mountingthe operating member in a spaced relation with the switch members toeffect operation of the switch members in sequence between a pluralityof circuit controlling positions upon corresponding movement of theswitch operating member, and automatic means associated with themounting means for automatically eifecting movement of the operatingmember from said spaced relation with the switch members in accordancewith certain conditions to effect operation of the switch members to apredetermined circuit controlling position.

2. The combination of a movable switch member, a rotatable cam operatingmember therefor, means for mounting the cam member with the axis ofrotation thereof in a position to effect operation of the switch memberbetween a plurality of positions upon rotation of the cam member, andmeans sociated with the mounting means for shifting the axis of rotationof the cam member to effect operation of the switch member to apredetermined position.

3. The combination of a movable switch member operable between thecircuit closing and the circuit opening positions, a cam operatingmember therefor, means for mounting the cam operating member with theaxis of rotation thereof in a position to effect operation of the switchmember between said positions upon rotation of the cam member, and meansassociated with the mounting means for shifting the axis of rotation ofthe cam member to effect operation of the switch member to the circuitopening position independently of the angular position of the cam.

4:. The combination of a movable switch member, operating means thereforincluding a rotatable cam, means for mounting the cam in a predeterminedspaced relation with the switch member to effect operation of the switchmember between a plurality of positions upon angular movement of thecam, and automatic means associated with the mounting means foreffecting movement of the cam out of operating relation with the switchmember to effect operation of the switch member to a predeterminedposition independently of the angular position of the cam in response topredetermined conditions. 7

5. The combination of a plurality of movable switch members, arelatively movable manual operating member therefor, means for movablymounting the said relatively movable member ina spaced relation with theswitch members to effect operation of the switch members in sequencebetween a plurality of circuit controlling positions upon correspondingm-ovement of the relatively movable member, electroresponsive meansassociated with the mounting means for automatically effecting movementof the relatively movable member from said spaced relation with theswitch members in accordance with predetermined electrical conditions tothereby automatically effect operation of the switch members to apredetermined circuit controlling position.

6. The combination of a switch member movable between a plurality ofpositions and biased to one of said positions, means for operating theswitch member between said positions, including a rotatable cam movablemeans for mountin the cam with the axis of rotation thereof? in aplurality of positions with respect to the switch member, one of saidpositions permitting movement of the switch member between a pluralityof circuit controlling positions upon corresponding angular movement ofthe cam, and automatic means associated with said monnting means forefiecting movement of the axis of rotation of the cam to anotherposition to permit movement of the switch memher in accordance with itsbias irrespective of the angular position of the cam in response topredetermined conditions.

7. A circuit controlling device comprising a switch member biased to thecircuit opening. position, operating means for the switch memberincluding a rotatable cam, means for mounting the cam with the axis ofrotation thereof movable between a plurality of positions, one of saidpositions permitting the cam to effect movement of the switch member toand from the circuit closing position upon corresponding angularmovement of the cam, and electroresponsive with said mounting means foreffecting movement of the axis of rotation of the cam to anotherposition to insure operation of the switch member to the circuit openingposition in accordance with its bias irrespective of the angularposition of the cam upon the occurrence of predetermined electricalconditions in the circuit controlled by the switc member.

8. The combination of a plurality of movable switch members, eachoperable between a plurality of circuit controlling positions, a commonmanual operating means for operating the said switch members each waybetween-said positions in a predetermined sequence upon predeterminedmovements of the operating means, and automatic means for effecting adifferent movement of the said operating means to insure simultaneousoperation of the switch members to predetermined positions in responseto predetermined conditions.

9. The combination of a plurality of movable switch members, eachoperable between a plurality of circuit controlling positions, operatingmeans including a movable member operable between a plurality ofpositions for effecting successive operation of the movable switchmembers between said circuit controlling positions, said movable memberbeing mounted for movement to a different position to effectsimultaneous movement of the switch members to predetermined circuitcontrolling positions and electroresponsive means for controlling themovement of said operating member to said different position inaccordance with predetermined electrical conditions.

10. The combination of a plurality of mov able switch members, operatingmeans therefor including a rotatable cam shaft having cams for effectingoperation of the switch members in a predetermined sequence uponrotation of the cam shaft about its axis, and means for effectingmovement of the axis of rotation of the cam shaft to permit simultaneousmovement of the switch members to a predetermined circuit controllingposition independently of the angular position of the cam shaft.

11. A circuit controlling device comprising a plurality of movablymounted switch members each having a plurality of circuit controllingpositions and biased to one of said positions, operating means thereforincluding a cam shaft provided with a plurality of cams for effectingoperation of the switch members between said circuit controllingpositions in a predetermined sequence, means for rotatably mounting thecam shaft with the axis of rotation thereof in a plu.-

rality of positions one of said positions insuring sequential operationof the switch members upon angular movement of the cam shaft, andelectroresponsive means for effecting movement of the axis of rotationof the cam shaft to a difierent position to permit simultaneousoperation of the switch members in accordance with their biasindependently of the angular position of the cam shaft in response topredetermined electrical conditions.

12. A circuit controlling device comprising a plurality of switchmembers each mounted for movement between the circuit closing and thecircuit opening position and biased to the circuit opening position,operating means therefor including a rotatable cam shaft having aplurality of cams arranged to effect successive operation of the switchmembers from the circuit opening po sition to the circuit closingposition, means for movably mounting the cam shaft in operative relationwith the switch members with the cam shaft biased out of said operativerelation to permit the simultaneous op eration of the switc members tothe circuit opening position in accordance with their bias, andelectroresponsive means energized in accordance with the current in thecircuit controlled by the switch members forcontrolling the movement ofthe cam shaft in accordance with its bias.

In witness whereof, I have hereunto set my hand this 20th day of August,1927.

FRANK E. CASE.

